STUDY OF THE BRAKING PROCESS OF A GRAIN HARVESTER USING VOLUME HYDROTRANSMISSION GST-90

Based on the analysis of transmissions of modern grain and fodder harvesters "Don", "Niva", "Yenisei", "KSK", "John Deere", "Challenger", "New Holland", "Class", road construction and reclamation machines, it was found that they are mainly equipped with a volumetric hydraulic drive of the GST-90 type. According to the data of the scientific and technical literature, in the transmissions of modern equipment for the agro-industrial complex, these reasons account for at least 35 %, including the failure of hydrostatic transmissions of the GST-90 type accounts for 20 % of the total number of machine failures during the pre-repair period of operation. Therefore, the development of mathematical models and the research of the braking process of grain harvesters using volumetric of the GST-90 hydraulic transmission will allow to increase efficiency, reduce wear resistance and increase the resource of its operation. It was found that with the widespread use of hydrostatic transmissions in grain harvesters, little attention is paid to the issue of effective braking using this type of transmission. The main goal of the article is to study the operation of the hydrostatic transmission in the braking mode. The calculation scheme of the GST-90 hydrostatic transmission was developed and its mathematical model was developed, which adequately reflects the processes occurring in the hydraulic transmission of the grain harvester in braking mode. This mathematical model can also be used for conducting research in order to develop recommendations for the design and selection of optimal parameters of a hydraulic transmission of this type. The developed mathematical model calls for further theoretical and experimental research to develop measures to increase the quality indicators of its characteristics.